Multiple pump for hydraulic systems



Dec. 24, 1946. H, J, MCGOVERN MULTIPLE PUMP FOR HYDRAULIC SYSTEMS original Filed Aug. 5, 194 2 sheets-sheet 1 Dec. 24, 1946. H 1, MCGOVERN 2,413,240

MULTIPLE PUMP FOR HYDRAULIC SYSTEMS Original Filed Aug. 5, 1942 2 Sheets-Sheet 2 57 85 Blf 56 53 --44 55. 672. 4! f2. gull llununlum In uuml] uw f'lI Hafllllrli llrl'llsls I L /fa L INVENTOR.

Patented Dec. 24, 1946 I MULT'BLE PUMP FOR HYDRAULIC SYSTEMS Harold J. McGovern, Rock Island,` Ill.

Qriginal application August 3, 19.42, Serial No. 453,334. Divided and this application October 17, 19.44, Serial No. 559,059

(Cl. 10S-I1) 4 Claims.

My invention has` reference to a pump for a hydraulic system, and is speciallf,7 designed for use with a hydraulic jack or ram, such as are employed in the lifting ,of the truck part of a semi-trailer outfit, more specially when it is provided with a load. It involves an arrangement employing two pairs of pumps, of different capacities, and in its original showing was divided out of an application led by applicant August 3, 1942, in the Patent Office of the United States, Serial No. 453,334, for a Pump for a hydraulic system, which later ripened into Letters Patent No. 2,337,831, under date of December 28, 1943.

One of the purposes of the invention is to have the two. pairs of pumps working in unison or separately, as desired, so that when the pressure is increased to a point to make the operation diiiicult the use of the larger pumps can be discontinued, and additional pressure built up by the use of the smaller pumps.

There is also shown and described herein a modified and improved form of the invention, increasing the efficiency and ease or handling of the apparatus, with a means for uniting the operating devices for the pumps in a joint operation, or disconnecting the same to permit the operationof one thereof independently o the other.

The foregoing, and other features and' advantages of the invention will more fully appear from the following specification, reference being had t the accompanying drawings, in which:

Fig. 1 is a plan view of a casing embodying the invention, somewhat diagrammatic, and with broken lines to indicate concealed passages.

Fig. 2 is a similar view of a modied arrangement thereof.

Fig. 3 is a fragmentary detailed showing of a part of Fig. 2, enlarged, with central parts in section.

Fig. 4 shows one ci the bushings is in side view. V

Fig. 5 is an end view thereof.

Fig. 6 is a side elevation showing one of the operating frames partly broken away.

Referring to the showing in l, the numeral 6 indicates the upper plate of a pump casing, upon which is mounted a pair ci cylinders I and 8, provided with piston rods S l0, pivotally connected with a hand-lever il, fixed on a post I2, iixed on a plate secured to the outer face of the plate t. Within the casing the cylinders 'l and 8- communicate with passages lf3 and I5, connecting at their upper ends with` a channel I5, extending lengthwise oi the casing, and

aty their lower ends: with a channel Il, parallel withI the first-named channel.

Entering the channel I 'l at the lower side-of the easing isan intake pipe I8., leading from a source of hydraulic supply, not shown in the drawings. In the upper part of the casing are outlets I9 and 20, leading from the channel. it., inl which are the ends ofV pipes 2| and 2?., leading tohydraulic jacks or other pressure control apparatus. Said pipes are provided, respectively, with cut-out valves 23 and 24 so that the iiow through either one or both of said pipes can be interrupted, each of said valves being provided with a handle 25 for operation.

Also mounted on` the casing li is` a pair ol cylinders 2l and 28., provided ywith piston rods 29,V connected with` pistons in the cylinders, not shown herein. The ends of said rods are pivotally connected with a hand-lever 30, fulcrumed on a post 3l, also iixed on the plate I3, and parallel with the lever Il, The inner ends of the cylinders 21 and 2.8, the capacity of which is considerably less than that of the cylinders 'I- and 8, areconnected with, passages 32 and 33, the ends of which open into the channels I6 and I1. The lower ends of said passages are ttedwith checkvalves 34, and the upper ends with check-valves 35,. The passages Ill and I5 are shown ii-tted with, similar check-valve apparatus in, their lower endsat 36j, and in their upper ends at 35a..

The ends of the handles. ll and 3 0 project beyondl the end-s of the casing- 6 and are suiciently close together to permitl the ends to be grasped by one or bothhands of the operator, and the4 leversr simultaneously rockedl von their iulcru'ms. This results in a workingY of all of the pumps and rapid building up ci the operative force in the casing and connected jacks. As the resistance increases there is a tendency ot the pistons in the` larger cylinders becomingY inactive, whereupon the operation of` the lever II is discontinued, and the pumping proceeded with by the use ci the lever 30 alone, continuing the movement of the pistons in the smaller cylinders, and causing an additional movement in. the pressure apparatus. The resistance oi the pressure. against these sinallerpistons is relatively` provided with,` a valve-stem indicated in, part at 39. The valve is normally closed, but upon being opened a release of the pressure results.

The levers Il and 30 are set forth herein as being at 'one side of the casing, in a horizontal position, `but they are not limited to such' an arrangement as the positioning can be changed, so that they will be projected above the casing,

or below the same, or at either side thereof. The

apparatus can be adapted for use not only with hydraulic jacks and rams, but with other structures under similar pressure control.

In Fig. 2 of the drawings the numeral 40 indicates the upper plate of a pump casing, in which is mounted a pair of cylinders 4| and 42, with piston rods 43 and 44, connected with pistons not shown in the drawings. Said piston rods are pivotally connected with a lever device consisting of a frame 45, formed of a pair of parallel spaced bars, fulcrumed at a central point on a post 46 mounted on a plate 46a secured to the plate 40. At its outer end there is xed to the frame 45 a handle 41, by means of which said frame can be rocked on its fulcrum. 'I'he inner ends of the cylinders 4| and 42 are connected with passages 48 and 48a in the body of the casing, and the ends of said passages communicate with similar passages 49 and 50 in the body of the casing or block, shown herein in broken lines. The rstnamed passages are fitted with check-valves at 5| and 5|a to prevent the return of hydraulic medium therethrough.

The casing 40 is also provided with a pair of cylinders 52 and 53 of larger caliber than the first-named pair of cylinders in said casing, pivotally connected with which are the outer ends of piston rods 54 and 55, connected with pistons in the last-named cylinders. The rods 54 and 55 are united by a lever formed of a pair of parallel frame pieces 56, fulcrumed on a post 51 mounted on the plate 46a. The ends of the frames 56 are united by bolts 58, with perforated spacers 59 separating the same. Ihe inner ends of the cylinders 52 and 53 are connected with passages Ilill and 6|, respectively, also in communication with the passages 49, and 5U, and provided with pairs of check-valves 62 and 63.

An intake pipe 64 communicates through the passage 50 with the passage 60, and is designed to conduct a supply of hydraulic medium into the interior system. Outlets 65 and 66 are provided, connecting with which are pipes 61, leading to the hydraulic system to be supplied with pressure, and provided with cut-out valves at 68. In passing to these outlets the medium passes through the several check-valves, and is restricted thereby from eiecting a return movement.

It is to be noted that in the arrangement shown in Figs. 2 and 3 the cylinders of less diameter are nearer the fulcrum points than the larger ones, which results in a reduction in the piston movement and the operation of the smaller pistons when driven alone with less exertion than required for the larger ones with their increased leverage and capacity. The operation is substantially the same as set forth in said former patent. When the resistance becomes sufciently strong the movement of the larger cylinders is halted, and the power applied to the small cylinders alone, with a, further building up of the pressure.

The fulcrum supports of the frames 45 and 56 are of a special character. and consist of a pair of bushings and 1I, which are square in crosssection, and are provided at a central point on their outer surfaces with circular collars 12, forming bearings in similarly shaped openings 13 in the posts 46 and 51. Said bushings are of hollow formation, to receive a bolt 15 of similar .rectangular form, extending for the length of the bushings and compelling a joint movement of the bushings and frames upon either thereof being given a rocking movement. The bolt 15 is projected at one end into a rounded pin 16, ending in a handle 11. At the ends of said pin are washers and 8|, against which bear the ends of an extensile coiled spring 82, tending to hold the pin in outer position. Said spring possesses a considerable amount of flexibility, permitting the handle to be forced toward the frames until one end of the bolt clears the inner end of the bushing 10, with the other bushing and frame .thereof free to be rocked independently. This of the bolt, and preventing its release on the handle side of the frames.

When it is desired to resume operation again with all four cylinders the handle 11 is released vfrom the keeper, and the bolt 15 returned to its original position in both housings by the force of the spring 82.

The double form of levers 45 and 56 is found to j be convenient and eiiicient, but the use of other forms thereof is possible, without departing from the spirit of the invention.

What I claim, and desire to secure, is:

l. In a pump for hydraulic systems, a casing provided with a plurality of passages for the conduct of a quantity of hydraulic fluid, having an intake at one point in the casing, and one or more outlets opposed thereto, a pair of cylinders mounted on the casing and communicating with said system, provided with pistons and rods therefor, a hand-lever fulcrumed midway said pistons and pivoted thereto, a second pair of cylinders of smaller diameter mounted on said casing, also communicating with said system, and provided with pistons and rods therefor, and a hand-lever operatively connected with said last-named rods, adapted for the independent operation of the las t named rods and pistons, the ends of said handlevers being adapted for grasping by the hand of thedoperator to cause a joint operation of all of said pistons during the initial operation of the device.

2. In a pump for hydraulic systems, a casing provided with a plurality of passages for the conduct of a quantity of hydraulic medium, having an intake at one point in the casing and one or more outlets disposed oppositely to the intake, a pair of cylinders mounted on the casing and communicating with said system, provided with pistons and rods therefor, a lever pivotally connected with said rods, and fulcrumed intermediate the same on said casing, means for rocking said lever on its fulcrum, a second pair of cylinders mounted on the casing, varying in diameter from the first-named cylinders, also provided with pistons and piston rods therefor, a lever connecting said piston rods, and fulcrumed on the casing intermediate the same, in line with the first-named fulcrum, means for locking said levers for joint, operation, releasable to permit independent operation of each thereof.

3. In a pump for hydraulic systems, a casing provided with a plurality of passages for the conduct of a supply of hydraulic medium, having an intake at one point in the casing and one or more outlets opposed thereto, check-valves in said passages preventing return movement of said medium, a pair of cylinders mounted on said casing, communicating with said system, and provided with pistons and rods therefor, a lever connecting said rods and fulcrumed on the casing intermediate the same, means for actuating said lever, a second pair of cylinders on said casing, relatively larger than the rst-named pair, and provided with pistons and rods therefor, a second lever connecting said rods, and fulcrumed intermediate the same, a spring controlled lock uniting said levers for joint operation, and releasable to permit independent action of the first-named pair of pistons.

4. In a pump for hydraulic systems, a casing 6 provided with a plurality of passages for the conduct of a hydraulic medium, provided with an inlet at one rpoint and one or more outlets opposed thereto, check-valves in said system preventing return of said medium, a pair of cylinders on said casing, in communication with said system, and provided with pistons and rods therefor, a lever frame connecting said piston rods, fulcrumed intermediate the same on said casing, and provided with an operators handle, a second pair of cylinders on said casing, also communicating with said system, and provided with pistons and rods therefor, a second lever frame connected with the last-named rods, and fulcrumed intermediate the same on the casing, in line with the firstnamed fulcrum, a bolt uniting said lever frames for joint operation, a spring yielda'bly connected with said bolt permitting movement thereof to free the first-named lever frame for independent action, and releasable to return the same to position for joint action of said frames.

HAROLD J. McGOVERN. 

